There is a mandatory field with required input provided as hint below.
The field is only visible and the check working after you've assigned a value
to the new option register_basic_token.

"Plan B" in the list of suggested improvements for new user registration is
a hidden input field, that might get only ever filled by bot clients.
Unlike the other one above this check always works - without configuration.

Added preview rendering of movies. Previews are rendered for attachments and repository files. For preview rendering to be available for all attachments, set the value of the [mimeviewer]max_preview_size configuration entry to greater than or equal to the value of the [attachment]max_size configuration entry in trac.ini.

Upgraded jQuery UI from 1.7.2 to 1.7.3, which resolved the mimetype issue described in comment:2. It is unlikely the upgrade itself fixed the issue; rather it may have been resolved simply by including a clean instance of jQuery UI 1.7.2.

FIX: The form controls were moved outside of the enclosing form elements in [12005], which caused them to stop working.

FIX: The class backlog was being used in multiple places within the backlog and backlog_list templates, which resulted in all of the elements being movable on the backlog page.

The dynamically-generated permission set was causing problems described in comment:4. In the future, fine-grained permissions will be implemented as part of the redesign. For now, the permission set is BACKLOG_VIEW, BACKLOG_MODIFY, BACKLOG_OWNER and BACKLOG_ADMIN.

Refs #10330: The fix in [12003] didn't work with Trac 0.11 because the from_timestamp function doesn't exist in that release. The fix was over-complicated anyway. It is not necessary to convert the timestamp to a datetime object because the pretty_timedelta function can take a timestamp as input.

Refs #10330: Fixed out of range timestamp issue on Trac 0.12+ due to the change to storing timestamps in microsecond format. Additionally, the pretty_timedelta function is now used to display the time open parameter.